If opening a multi-volume archive, the path of the first volume should be passed as the first parameter.
Otherwise, not all files will be shown. This is by design.

Parameters

filename

Path to the Rar archive.

password

A plain password, if needed to decrypt the headers. It will also be used by default
if encrypted files are found. Note that the files may have
different passwords in respect to the headers and among them.

volume_callback

A function that receives one parameter – the path of the volume
that was not found – and returns a string with the correct path
for such volume or NULL if such volume does
not exist or is not known. The programmer should ensure the
passed function doesn't cause loops as this function is called
repeatedly if the path returned in a previous call did not
correspond to the needed volume. Specifying this parameter omits
the notice that would otherwise be emitted whenever a volume is
not found; an implementation that only returns NULL
can therefore be used to merely omit such notices.

Warning

Prior to version 2.0.0, this function would not handle relative
paths correctly. Use realpath() as a workaround.